1. Field of the Invention
The present invention relates to life rafts, flotation aids and signaling devices for the man over board. More particularly to the use of manual means of pneumatic and hydraulic manipulation of chambers, floors or hulls of the life raft whose volume can now be continuously adjusted to meet changes in occupant load, weather conditions and availability or rain water to be stored for drinking. The present invention also relates to the provision of airway protective flotation aids, multi-modal thrown, self orienting manual and water activated signaling devices for the Man Over Board (“MOB”). More particularly to the application of compressed liquid gas and foam and use of a water-activated switch to alert rescuers while providing buoyancy and conserving warmth.
2. Description of the Prior Art
Life rafts rely upon compressed gas to achieve structural integrity. Instantaneous deployment is an expectation of life raft performance that ties the life raft to compressed gas inflation with the steel cylinder's burden of weight, bulk, cost and maintenance. Further the strict reliance upon compressed gas inflation limits the internal volume to displacements compatible with acceptably sized cylinders. While large offshore sailboats can afford the cost, can carry the weight and have the space to spare for a compressed gas inflated life raft it is the small vessel which ply the same ocean without a buoyant alternative outside of their life jacket. While a life jacket is critical in surviving an unexpected water entry, it is well established that for many temperate coastal waters personal flotation devices (“PFD”) mediated airway protection improves survival only for 30 to 60 minutes. Without a water exit strategy completed within that time period the survivor even while floating face up in their PFD dies of exposure.
Needless to say the vast majority of boating fatalities occur on vessels less than 26 feet in length. It is not coincidental that the it is the small vessel which has neither the space nor budget to afford a traditional compressed gas life raft system that bears the consequences. The large steel cylinder used to inflate the single person life raft is stored with the raft in a pan beneath the pilot's ejection seat. The jet has the capacity to store and carry the compressed gas system required for inflating the one-person life raft but that same size raft with its requisite inflation is much to bulky, rigid and heavy for routine inclusion in the flight deck jump suit, consequently the majority of flight deck crew blown off aircraft carriers are rarely found alive.
The continued reliance upon compressed gas to inflate even the smallest one person life raft has clearly blocked the consideration of life raft for use in ocean kayaks, personal water craft, small water craft yet alone garments and PFDs, without which survival success is clearly defined in minutes. The mandate for inflation of the life raft by compressed gas drove the designer to limit the size and function of a life raft to a single inflation of fixed-volume chambers. The chamber's capacity and design is fixed and limited to the size cylinder selected for a particular raft. The cost, weight and space of the first compressed gas cylinder clearly prohibits inclusion of a back up cylinder. Consequently, once the cylinder pressurizes the raft, its fixed-volume chambers are considered inviolate. Once the compressed gas cylinder is empty it is useless.
If you generally sail with a crew of four, you are likely to purchase a 4 person life raft. If unexpected guests joined you the day you need a life raft, you make concessions and overload the fixed-displacement provided by the 4 person raft/cylinder. If you are on a commercial vessel that has five 10-person life rafts and three do not release and the boat was slightly overloaded when it left the dock, you may find your self and twenty others trying to get in or hang on to a fixed-volume ten person life raft until it is awash beneath the load.
Books are filled with stories of survivors spending weeks, months, often many months at sea. The rule is that five vessels will motor past you before one sees you adrift in your life raft so it behooves you to be seen a lot and hope some vessel has a live pilot at the helm. After the first 48 hours of storms during which the drogue and perimeter Icelandic ballast system failed to prevent the raft from tumbling down the face of several waves, fair weather has finally returned. As you are recalling that the shipping lanes are only 10 miles down wind you feel the hydrodynamic drag or the same undersized self-filling Icelandic ballast system now markedly slowing your Course Made Good and wonder why the sea anchors are not also self-emptying.
The one general principle of extended survival at sea is, survival=water. It is recognized that you can go weeks or months with little or no food but without water, survival is measured in days. The air force ejection seat life raft is provide with three 9 oz containers of water but then a jets path and progress is continually monitored and search and rescue efforts are quickly launched if you stray from the flight plan. Even so 27 ounces of water seems marginal for survival at sea. You cannot carry enough for 30 or 144 days. While there are brief squalls, the torrential down pour quenches the survivors thirst for only a moment. The survivor never knows how long till the next cloud burst. If the survivor was able to collect a quart or gallon from the down pour, the raft's continual exposure to contaminating salt water spray and restless sleep is likely to upset any jury-rigged storage system sharing the two square feet allotted per person in a life raft. After the rain, the survivor bails out the rainwater in the bottom of the raft, washing off the salt crust, fish scales and fish remains as well as any residual excrement with now un-potable brackish rain water. Before the last rain is bailed the survivor loathes the searing afternoon sun and fears the return of unquenched thirst. The survivor is desirous of re-inflating the canopies arch for protection from the sun but lacks the intercostal strength to orally rigidify the canopy struts.
The 100+ day survival scenarios detail the ultraviolet damage to the raft, the loss of laminate, the abrasion that portends bladder failure. The gaunt survivor has no back up compressed gas cylinder and oral inflation has grown very difficult over the months. While the bon voyage revelers supplied the sailor with a high quality dual ring off shore life raft, the lower ring failed last month upon impacting a shipping container one night and now lies limp beneath the last buoyant perimeter ring separating the survivor from the sea. The survivor is concerned about the growing ulcers on his backside where he initially sustained lacerations when his sailboat pitch-poled through the night before sinking so fast that few supplies were gathered before he stepped up to the life raft. It seems the dorados know when he is no longer lying on his side and bash against the bottom of the raft seemingly with intention. If he only had a fishing pole he would pursue a revenge on those head bangers of the open ocean. There is already a slow leak where the dorados insist on trying to tear through the raft floor to chew on what's left of his backside poking down in the ocean.
Thus there is need for a raft that can be quickly inflated without dependence upon compressed gas inflation. A system that can inflate the raft within the 30 minute window of opportunity in order to avoid the loss of consciousness due to exposure. A system that will allow a chamber deflated secondary to puncture to be repaired and re-inflated at sea to full structural and functional pressure. An inflation system that can be used daily to support the rafts pneumatic structure as the raft fabric deteriorates in the scorching sun. An inflation system that can be operated by a weakened survivor. A raft and inflation system light enough for comfortable routine inclusion in garments, PFDs and small vessels. A raft whose displacement can be quickly increased or decreased to meet changing occupant loads and weather conditions. Since an under-loaded raft can be as dangerous as an overloaded life raft, the raft needs means for both filling and emptying a sea ballast system. A ballast system sized to create reliable adhesion to the water's surface at one moment but allow the drag to be just as quickly eliminated survival now demands the raft achieve a course made towards a trafficked shipping lane. In particular there remains a need for a raft that will allow rain water to be effectively captured and quickly transferred to a container that will protect the drinking water from salt water, fish remnants, urine other bodily by-products. A hydration chamber with means to assure the survivor that the all the water stored can be recovered from the raft lest delusion drives to survivor to slash the floor in a desperate attempt to recover entrapped drinking water. Further there is a need for the raft to insulate the survivor from hypothermic waters and cushion the survivor from the Dorados relentless banging on the bottom of the raft.
Current air horns can only be used when held in the upright position precluding their use as a thrown safety device. In positions other than vertical the liquefied/pressurized contents submerge the open vent and the liquefied contents spew from the horn. Their rapid conversion from liquid to gas is highly endothermic producing damage secondary to freezing where ever the contents land. If the arm is drawn over the head the liquefied gaseous contents are likely to be blown all over the head and face as well as hand and arm damaging or destroying the cornea and producing frost bums over exposed skin. Thus there is a need for a gaseous drawing system that only allows the gas contents of an aerosol can and not its liquefied gas contents to pass through the open valve.
Some air horns are actually negative when full and will sink. Under water they bubble rather than blare that is they are of no value in serving as a marker of a MOB. Thus there is a need for positive net buoyancy to keep the device on the surface
Current air horns are restricted to up right usage as warned on the label yet once adapted to be thrown as a MOB Signaling device when they land in the water the air horns position at the waters surface is critical to their signaling function. Heavy long flared openings to the horn have cosmetic appeal to a device held upright on a vessel or dock yet the amplified ballast effect of the plastic on a leveraged arm positions the horn so that it submerges the horns exit orifice. Current air horn designs for upright land use enclose excessive buoyancy behind the axis of effective out of water operation. The rear buoyancy combines with the forward ballast of the dramatically flared portion of the horn to place the exit orifice in a water submerged position. Thus there is the need for the addition of closed cell foam or enclosed space within the horn and complementary high density ballast to orient the air horn as it goes through its dramatic loss of ballast as it liquefied gas contents are consumed keeping the MOB signaling horn pointed operationally into the air.
The amount and location of an air horns net buoyant moment shifts dramatically as the liquefied gas contents are converted to gas and then expelled through the open valve. When the air horn is full the liquefied contents in the metallic can assume a diametric position from the buoyant enclosed plastic horn portion. As mentioned some actually sink in the vertical position. As the liquefied contents are consumed the can goes from ballasting to buoyant and rises up going through a range of angles starting with 90 degrees when negative to 0 degrees when near empty. Thus there remains a need to add buoyancy if not ballast and buoyancy to assure the air horn does not sink and remains pointed in an out of the water position across its entire operational life cycle.
The oscillating membrane of commercially available air horns varies widely. The small 1.5-oz air personal air horn is designed to save construction costs. Inexpensive small horns fail within a minutes if the valve is held open. The larger horn designed for vessels up to 40 ft in length and measuring 10 inches are capable of continuous use with out the membrane failing under continuous exposure to freezing temperatures. The current air horn is designed for short blasts, even if the horn membrane is capable of extended use the can is so cold it can not be held with the bare hand.
Existing water activated systems used to inflated PFDs are so expensive as to preclude its inclusion in the air horn. Even if one could afford to but such a safety device many would be reluctant to use it given some rearm kits cost in excess of $49.00. The toddler's room is often monitored for breathing difficulties or other signs of distress by commonly found transmitters and receivers yet numerous toddlers drown each year when they fall unmonitored into the tub, toilet, pool or off the dock into a pond. The young toddler unable to speak cannot respond to his parent's calls and may have wandered into the basement or out of the house where he could come into harms way. The same child may be lost in the mall or park remaining silent despite their parent's plaintive calls and efforts to locate them. The older child may have wandered from their parent under the behest of a stranger when sudden the child becomes alarmed and wishes to reestablish contact.
Numerous toddlers drown each year when they fall unmonitored into the tub, toilet, pool or off the dock into a pond despite the common presence of transmitters found in the child's room often monitoring for breathing difficulties or other signs of distress. Currently the parent or guardian often carry a base station device on their person as they conduct their various activities or have a fixed station plugged in at their home office. It may be assumed the silence of child whose has just toddled out of their room is evidence that every thing is fine when in fact the child may have just fallen in a bathtub or back yard splash pool.
The young toddler just learning to speak may listen attentively rather than respond to his parent's urgent calls. The child may have wandered into the basement or out of the house where he could come into harms way. The same child may have slipped into a different isle at the mall or have gotten lost at the park remaining silent despite their parent's plaintive calls and efforts to locate them. The older child may have wandered from their parent under the behest of a stranger when suddenly the child senses the mounting danger, becoming alarmed they may wish to re-establish contact with their parent.
Currently there are many distress signal markers and flashlights marked at water proof to hundreds if not thousands of feet. Such water proof flashlights are suggested for use in boating emergencies and for attachment to their life jackets yet it is widely accepted that a panicked, disoriented if not unconscious victim of an unexpected water entry may unable or simply have forget to turn on their distress light. Such waterproof flashlights contain a reliable housing, providing dry and protected power sources and already provide one modality of signaling. Clearly a steady 3.0 volt light maybe of little use during a daytime man over board incident. If a guest unfamiliar with the equipment attached to their PFD panics, becomes confused or unconsciousness the victim may not manually turn on their distress light even during a night time disaster at sea.
The reliability of the inflatable PFD remains a serious concern. The ability to accidentally re-install a spent CO2 cylinder along with the new water activated wafer leaves the PFD seemingly ready to provide buoyancy and corrective turning yet unable to in event of a man over board emergency. The threaded cylinder that was loosely installed or loosened during storage in a vibrating ship's locker in another frequent cause of inflatable failures in the real world. Further the vagaries of the welded fittings and whether or not the mold parting solution was fully removed prior to welding can lead to problems that may not appear until after the first or second inflation. Fully redundant chambers provide an improved level of protection at considerable cost of fixtures, fabric and bulk. Dual chambered PFDs, which share a common wall, provide the redundancy of inflators and cylinders at reduced cost but are more prone to a catastrophic failure due to puncture. The susceptibility of inflatables to puncture around shredded steel cable, railings or flotsam in the event of a disaster at sea is undeniable.
The inherently buoyant PFD retains efficacy despite puncture, laceration or even avulsion but corrective turning requires excessive bulk rarely found in fielded products. Unfortunately the desire to compromise on bulk has produced an enormous amount of fielded product which provides positive buoyancy but fails to provide airway protective corrective turning action. The real challenge is whether the bulky foam PFD will be worn at the time of the accident or merely stowed somewhere aboard ship to meet carriage requirements.
It is an unavoidable fact that the bulk of the inherently buoyant PFD or the hybrid construction in which a component of the displacement is also provided by an inflatable element, is so bulky, hot and uncomfortable as to be incompatible with routine wear by anyone other than children under mandate from parents and the legal system. Mandatory usage of the inherently buoyant PFD akin to motorcycle helmets and seat belts may someday dictate wearage not carriage as the law punishable by fine. Such a situation is so onerous as to be vehemently opposed by those profiting from the sale, use and maintenance of pleasure boating craft. Despite clear knowledge that the worn PFD is of profound value in surviving the boating accident, carriage laws persist as sufficient despite knowledge that the PFD, which is carried is unlikely to be located by the unexpected water entry victim. It is so unlikely that the victim will find their life jacket that life jackets are not designed nor tested for their ability to be donned while in the water. So like the motorcycle helmet at home in the garage or the seat belt lying by the motorist's side, for the vast majority the inherently buoyant PFD or hybrid PFD is merely going along for the ride. While current Hybrid PFDs offer the performance benefits of both classes of PFDs, the airway protective corrective turning of the inflatable and the rugged durability of the closed cell foam PFD, they provide no benefit when merely carried because they are to uncomfortable to be worn.
Hybrid, inflatable and inherently buoyant PFDs are currently the subject of enforced carriage because of the documented role of life jackets in preventing boating fatalities. Ultimately reduced fatalities will rely upon the institution of fines or the design of invisible, comfortable PFDs. While the soldier maybe coerced into wearing a midline crossing PFD the recreational boater will not routinely wear any PFD that crosses the midline due to its sense of confinement. A recreational garment based PFD to be worn must be able to operate whether the jacket is mandatory usage closed, partially closed or fully open. If the victim of an unexpected water entry is fortunate enough to be wearing their PFD of choice prior to the accident, the second most important aspect of surviving a man over board event is to be noticed as missing. Before crew remaining aboard to immediately can initiate search and recovery efforts they must become aware that someone has fallen overboard.
The PFD community has been challenged by the USCG to design a cost-effective 16 gm airway protective life jacket. Nothing currently exists that can provide corrective turning with the minimal amount of displacement provided by a 16 gm CO2 cylinder. The current inflator that works with the UL approved threaded 16 gm CO2 has a ⅜ inch neck. That same ⅜ inch inflator can also mount a 25 or 38 gm CO2 either of which can seriously over inflate a bladder designed to achieve 1.6 to 2 psi on 16 grams. Current safe assembly relies upon operator reading imprinted warnings on the PFD and cylinder.
For the solo sailor, the man over board event is a very serious. An airway protective life jacket only addresses the first hour of survival. Hypothermia is a rapidly disabling and lethal condition for which water exit is the primary solution. As with the bulky life jacket a bulky personal life raft is more likely to be left aboard than be routinely worn when in or around water. Past personal life rafts required large collection bags and tubes that increased the amount of bulk during storage. A bulky life raft might be carried as a life raft for a small outboard motorboat but the packed bulk restricts their acceptance or incorporation to bulky foul weather gear and large PFDs. While one or more inflatable floors in a life raft provide increased protection from the hypothermic effects of oceans upon which they are floating hypothermia from wind blowing across wet clothes remains a threat to extended safety and survival at sea. It is discouraging if not terrifying for a survivor resting on top of an inflated floor to have to get back into the water and push the hydrostatic collector to 5 foot of depth. Additionally certain children or adults are not tall enough to develop the 2.5 psi required to create the degree of rigidity necessary for acceptable performance of the life raft in a mounting sea state. There are inflatable life jackets that inflate upon contact with water or water pressure however the initial cost of an automatically inflated PFD as well as the re-arming costs remain prohibitive for many open boaters.
For helicopter water rescue personnel their only choice is to use a manually activated inflatable PFD or no life jacket, neither of which provide protection in the event the rescuer's impact with the water results in the loss of consciousness. Since it is their occupation to first jump from a hovering helicopter into the water then to swim rapidly to the aid of a drowning victim, any foam or automatically inflated PFD would seriously impair their ability to execute a swimming rescue. Current inflators require attachment with a torque wrench and there are no facilities in the field to convert manual to water activated to hydrostatic activated. The cost of the inflator when it can not be transferred between bladders is such that it limits designs, which might benefit from replacing one or more inflatable chambers of a PFD without having to throw away the costly inflator mechanism. The dry suit in particular the ballistics dry suit is a particular case with the air retention of the dry suit easily supports the ballast of the heavies to tactical plates. Ballistics dry suits provide puncture protection as long as the ballistics impact is restricted to the very limited area protected by the body armor. In the event of direct or fragment impact outside that zone the dry suit looses its air and take on water converting from buoyant to ballasting. Attachment of an inflatable PFD through the waterproof membrane has restricted the introduction of the ballistics dry suit PFD.
Accordingly there remains a need, which is provided by the present invention, for a convertible hybrid PFD in which the inflatable component can be transferred between the inherently buoyant PFD and a wide range of recreational garments. Ideally a cylinder of compressed liquid foam attached to the main, back up or sequential bladder allows for user or water-activated conversion of some or all of inflatable PFD into a hybrid PFD. A synergistic and evolving combination of the durability of foam with the wear-ability of garment integrated inflatable. The movement of pressurized gas across reeds, edges and diaphragms creates multiple oscillatory elements, alerting crew or parents to the sudden onset of a man over board event. The use of locking quarter turn inflator and CO2 cylinder specific housings prevents PFD failure due to loose cylinders and prevents mismatching over sized cylinders to small bladders. The planar raft with minimal compressed gas inflates a perimeter tube and vertical struts allowing the survivor to immediately exit the water. The self-inflating personal life raft benefits from a large bore flapper valve built into a differentially cut floor and is complemented by a small torque pump which allows the panicked survivor to completely inflate the raft from inside the raft if so desired. The small torque bag can be used to bail the boat, manage emesis, collect and store rain water and well as orienting the craft in a following sea. The larger hydrostatic pump collector can also function as a self inflating thermally protective survival bag for use with the personal life raft to control heat loss. A reusable water or disposable ionic-enhanced water detection switch can be used to signal any water submersion event from man over board to toddler in the toilet through transceiver devices currently in wide use. Micro circuitry allows a device to be worn at the collar of the young toddler that will float the oscillator and antenna at or above the water's surface even if the child's face is under water. It is designed to be tested daily to confirm operation of battery and circuitry. Its child friendly appearance and sound encourages compliance. Its two-part structure reduces the chance of ingestion. The water or ion enhanced water switch combined with a solenoid and cam can be combined into a flexible water activated inflator. An electronic delay allows water rescue personnel to prevent automatic inflation if they maintain consciousness during the rescuer's jump from the helicopter but in the event of unexpected loss of consciousness on impact the inflator after the delay will provide air way protective turning to the unconscious rescuer. Any PFD, but in particular the liquid foam convertible hybrid PFD, benefits from the disclosed user transferable inflator so that bladders once filled with foam can be replaced by deflated bladders which can be re-armed in the field by use of the same inflators. Existing incandescent and LED manual operated flashlights can be modified to include automatic water or ion-enhanced water activated visual and or auditory and or RF signaling capacities as warranted. The dry suit can be modified to allow the reversible mounting of an inflatable PFD to offset a flooded suit, an expected occurrence in a ballistics dry suit. A quick release yet secure lock and key zipper pull allows the force of a deployed reversibly-mounted inflatable from inadvertently detaching itself after inflation.